Objective    To search for the common differentially expressed proteins in the substantia nigra of mouse models with Parkinson’s disease (PD) induced by rotenone and 1-methyl-4-phenyl-1

2

3

6-tetrahydropyridine (MPTP)

and to screen out the disease-specific proteins (DSPs) of PD.     Methods    Forty-eight mice were randomly divided into a rotenone group and its control group 1

as well as an MPTP group and its control group 2. In the rotenone group and MPTP group

rotenone and MPTP were given separately by injection to construct mouse models with chronic PD. Behavioral evaluation of the mice in the four groups was performed

and immunohistochemistry was carried out to detect the tyrosine hydroxylase (TH)-positive cells in the substantia nigra. Proteins were extracted from the substantia nigra and subjected to two-dimensional gel electrophoresis. Electrophoretogram analysis was performed using PDQuest 8.0 to find out the differentially expressed proteins between the rotenone group and control group 1 and between the MPTP group and control group 2. The differentially expressed proteins

after digestion

were subjected to MALDI-TOF-MS to obtain their peptide mass fingerprints for searching in a database and biological information analysis.     Results    There were significant behavioral differences between the rotenone group and control group 1 and between the MPTP group and control group 2 (P0.05). The numbers of TH-positive cells also showed significant differences between the rotenone group and control group 1 and between the MPTP group and control group 2 (P0.05). Twenty-two differentially expressed proteins were found between the rotenone group and control group 1

and twenty-eight were found between the MPTP group and control group 2

with seven common differentially expressed proteins. Three of the seven common differentially expressed proteins

PPP2R1A

pyridoxal kinase and peroxiredoxin-2

were identified in the database.     Conclusion    Three common differentially expressed proteins

not reported in the previous proteomic research on PD

are identified. Their up-regulated or down-regulated expression may be intimately related to the pathogenesis of PD. The three common differentially expressed proteins may be DSPs of PD.